Eccentric vibrator systems and methods

ABSTRACT

An apparatus that generates vibrational motion is disclosed. The apparatus includes a first mass, a second mass, a drive system, and a control system. The first mass is eccentrically mounted on, and configured to rotate about, a first shaft. The second mass is eccentrically mounted on, and configured to rotate about, a second shaft, with first and second shafts sharing a common axis. The drive system imparts rotational motion to first and second shafts, and the control system controls rotational frequencies, directions, and initial angles of the first and second masses. Linear, elliptical, or circular vibratory motion of the apparatus may be induced by controlling such rotational properties of the first and second masses. The apparatus may include a measurement device that measures angular position and/or velocity of the first and second masses. The control system may control the vibrational motion based on measurements taken by the measurement device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of currently pending U.S. patentapplication Ser. No. 16/279,838, filed Feb. 19, 2019, which claims thebenefit of U.S. Provisional Patent Application No. 62/632,348, filedFeb. 19, 2018, the entire contents of which are incorporated herein byreference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are an integral part of the disclosure and areincorporated into the present specification. The drawings illustrateexample embodiments of the disclosure and, in conjunction with thedescription and claims, serve to explain, at least in part, variousprinciples, features, or aspects of the disclosure. Certain embodimentsof the disclosure are described more fully below with reference to theaccompanying drawings. However, various aspects of the disclosure may beimplemented in many different forms and should not be construed as beinglimited to the implementations set forth herein. Like numbers refer tolike, but not necessarily the same or identical, elements throughout.

FIG. 1 is a transparent perspective view of an eccentric vibratorapparatus, in accordance with one or more embodiments of the disclosure.

FIG. 2 is a transparent side view of an eccentric vibrator apparatus, inaccordance with one or more embodiments of the disclosure.

FIG. 3A is a perspective top view of an eccentric vibrator apparatus, inaccordance with one or more embodiments of the disclosure.

FIG. 3B is a perspective bottom view of the eccentric vibrator apparatusshown in FIG. 3A, in accordance with one or more embodiments of thedisclosure.

FIG. 4 is an exploded view of an eccentric vibrator apparatus, inaccordance with one or more embodiments of the disclosure.

FIG. 5 is a cross-sectional view of the eccentric vibrator apparatusillustrated in FIGS. 3A and 3B, in accordance with one or moreembodiments of the disclosure.

FIG. 6A is a side view of a vibratory system, in accordance with one ormore embodiments of the disclosure.

FIG. 6B is a side view of a vibratory system, in accordance with one ormore embodiments of the disclosure.

FIG. 7A is a perspective view of a vibratory system, in accordance withone or more embodiments of the disclosure.

FIG. 7B is a perspective view of a vibratory system, in accordance withone or more embodiments of the disclosure.

FIG. 8 is a diagram of a vibratory system, in accordance with one ormore embodiments of the disclosure.

FIG. 9 is a schematic illustration of an eccentric vibrator apparatuscoupled to a control system, in accordance with one or more embodimentsof the disclosure.

FIG. 10A is a schematic illustration of an eccentric vibrator apparatuscoupled to a control system, in accordance with one or more embodimentsof the disclosure.

FIG. 10B is a schematic illustration of a vibrator apparatus coupled toa control system, in accordance with one or more embodiments of thedisclosure.

FIG. 11 illustrates time-dependent forces between mass members of aneccentric vibrator apparatus, in accordance with one or more embodimentsof the disclosure.

FIG. 12 illustrates time-dependent forces between mass members of aneccentric vibrator apparatus, in accordance with one or more embodimentsof the disclosure.

FIG. 13 illustrates time-dependent forces between mass members of aneccentric vibrator apparatus, in accordance with one or more embodimentsof the disclosure.

FIG. 14 illustrates time-dependent forces between mass members of aneccentric vibrator apparatus, in accordance with one or more embodimentsof the disclosure.

FIG. 15 is a block diagram of an example computer system, in whichdisclosed embodiments may be implemented, according to an embodiment ofthe present disclosure.

DETAILED DESCRIPTION

The present disclosure provides systems and methods of generatingvibratory forces to drive movement of vibratory industrial equipment orother types of equipment, including user equipment and consumerelectronics.

Disclosed embodiments include eccentric vibrator systems that mayproduce substantially linear, elliptical, and/or circular vibrations.Disclosed embodiments include vibratory systems that may utilize suchsystems. Disclosed systems may generate respective substantially linearsinusoidal forces that cause substantially linear vibrations. In someembodiments, a vibratory system may be mounted on equipment and mayexert a substantially linear sinusoidal force to thereby vibrate theequipment.

A disclosed control system may change an angle of motion and anacceleration of a screening machine. In one example, a slurry (e.g., asemi-liquid mixture) may be dewatered, and conveyed along a vibratingscreen of the screening machine under the influence of vibratory motion.The slurry may be transformed from a liquid-solid mixture to a dewateredsolid. To increase dryness of the material, disclosed embodiments allowa conveyance angle of the system to be adjusted, which increases liquidremoval from the mixture. For example, the conveyance angle may beincreased from 45° to 60°. An increased angle may reduce a flow rate ofmaterial moving upward on a screening surface, thereby allowing moretime for liquid to be driven from the mixture. Similarly, vibrationalacceleration of the system may be increased to increase removal of theliquid. Alternatively, vibrational acceleration may be decreased,causing less liquid to be removed, if a wetter discharge is desired. Indry screening applications, vibration of the material may also beincreased to reduce an occurrence of stuck particles in the vibratingsurface (i.e., to reduce screen blinding).

In one embodiment, an apparatus may include a first motor assembly and asecond motor assembly, both disposed within a housing assembly. Thefirst motor assembly may include a first shaft, and the second motorassembly may include a second shaft substantially collinear with thefirst shaft. The first shaft and the second shaft may be separateelements. The first motor assembly may also include a first plurality ofmasses attached in a location that is proximate to a first end of thefirst shaft, and a second, counterbalancing plurality of masses attachedproximate to a second end of the first shaft, where the second end ofthe first shaft is opposite the first end of the first shaft. The secondmotor assembly may include a third plurality of masses. This thirdplurality of masses may be attached proximate to a first end of thesecond shaft, adjacent to the first plurality of masses of the firstmotor. The second motor assembly may further include a fourth pluralityof masses serving as a counterbalancing plurality of masses for thesecond motor assembly, and being attached proximate to a second end ofthe second shaft, opposite the first end of the second shaft.

The first shaft and the second shaft may rotate at a defined frequencyand in opposite directions, causing the masses included in the apparatusto generate an essentially linear sinusoidal force. Alternatively, thefirst and second shafts may rotate in the same direction to generateelliptical or circular motion. In some embodiments, a control system maybe functionally coupled to the apparatus. The control system may controlrotation of first and second shafts, velocity, and/or position of massmembers to generate forces having predetermined amplitudes anddirections.

While some embodiments of the disclosure are illustrated in connectionwith industrial equipment, the disclosure is not so limited. Eccentricvibrator systems in accordance with this disclosure may also be used inany other device where vibrations are to be produced, for example, userequipment, consumer electronics, and other types of electronic devices.

FIG. 1 is a transparent perspective view of an eccentric vibratorapparatus 100, in accordance with one or more embodiments of thedisclosure. Eccentric vibrator apparatus 100 includes a housing assembly150 that may have an elongated shape defining an axis 102 (e.g., labeledwith a “z” in FIG. 1). Eccentric vibrator apparatus 100 may also includea first motor assembly 110 a and a second motor assembly 110 b, eachdisposed within housing assembly 150. In some embodiments, first motorassembly 110 a may include a first shaft 105 a oriented substantiallyalong axis 102, a first mass member 120 a mounted eccentrically on firstshaft 105 a, and a first counterbalance mass member 130 a mountedeccentrically on first shaft 105 a.

As shown in FIG. 1, first mass member 120 a may be attached proximate toa first end of the first shaft 105 a. First counterbalance mass member130 a may be attached proximate to a second end of first shaft 105 a.The first mass member 120 a and the first counterbalance mass member 130a may each include a plurality of members. In an embodiment, a firstmember of the first mass member 120 a and a first member of the firstcounterbalance mass member 130 a may be configured to be substantiallyin parallel and may be assembled at a defined angle around acircumference of the first shaft 105 a relative to one another. In oneexample, the defined angle may be approximately 180 degrees (e.g., asshown in FIG. 2 and described in greater detail below).

Second motor assembly 110 b may include a corresponding second shaft 105b oriented substantially along axis 102, a second mass member 120 bmounted eccentrically on second shaft 105 b, and a second counterbalancemass member 130 b mounted eccentrically on second shaft 105 b. Secondmass member 120 b may be attached proximate to a first end of secondshaft 105 b, where the first end of the second shaft 105 b is adjacentto the first end of first shaft 105 a. Second counterbalance mass member130 b may be attached proximate to a second end of the second shaft 105b, opposite the first end of second shaft 105 b. The second mass member120 b and the second counterbalance mass member 130 b may each include aplurality of members. A first member of the second mass member 120 b anda first member of the second counterbalance mass member 130 b may beconfigured to be substantially in parallel and may be assembled at adefined angle around a circumference of the second shaft 105 b relativeto one another. In an example, the defined angle may be approximately180 degrees (e.g., as shown in FIG. 2 and described in greater detailbelow).

The first mass member 120 a and the second mass member 120 b may eachhave a first net mass. Likewise, the first counterbalance mass member130 a and the second counterbalance mass member 130 b may each have asecond net mass. Various combinations of the first net mass and thesecond net mass may be chosen, with the magnitude of the second net massdepending on the magnitude of the first net mass, as explained in moredetail below. For example, the first net mass may be about 24.0 kg,while the second net mass may be about 3.0 kg. In some embodiments, eachmember of the first mass member 120 a may have a substantially circularsector shape having a radius of about 14.0 cm. Similarly, each member ofthe second mass member 120 b may have a substantially circular sectorshape having a radius of about 14.0 cm. Further, each member of thefirst counterbalance mass member 130 a may have a substantially circularsector shape having a radius of about 9.4 cm. Similarly, each member ofthe second counterbalance mass member 130 b may also have asubstantially circular sector shape having a radius of about 9.4 cm.Other embodiments may include mass members having other shapes,dimensions, and masses.

Eccentric vibrator apparatus 100 may generate a substantially sinusoidalforce with an adjustable magnitude and orientation along a directionsubstantially perpendicular to axis 102 (e.g., in the x-y plane). Inthis regard, first shaft 105 a is configured to rotate about axis 102 ina first direction at an angular frequency ω (a real number in units ofrad/s), and second shaft 105 b is configured to rotate about axis 102 atthe angular frequency ω, in a second direction. In certain embodimentsthe second direction may be opposite the first direction, while in otherembodiments, the first and second directions may be the same. Theangular frequency ω may have a magnitude of up to about 377 rad/s.Rotation in the first direction causes first mass member 120 a toproduce a first radial force F_(a) that is substantially perpendicularto a trajectory of circular motion (i.e., perpendicular to the velocity)of first mass member 120 a (as described in greater detail below withreference to FIGS. 11 to 14). Similarly, rotation in the seconddirection causes second mass member 120 b to produce a second radialforce F_(b) that is substantially perpendicular to a trajectory (i.e.,perpendicular to the velocity) of circular motion of second mass member120 b. Rotation of first shaft 105 a and second shaft 105 b about axis102 may yield a resultant force that is substantially contained within aplane perpendicular to the axis 102 (e.g., in the x-y plane). A linearlyoscillating force may be generated when first 105 a and second 105 bshafts are counter-rotating. Alternatively, a force corresponding tocircular or elliptical motion may be generated when first 105 a andsecond 105 b shafts are co-rotating, as described in greater detailbelow.

A magnitude of the first force F_(a) may be determined, in part, by theangular frequency w and the moment of inertia of first mass member 120a. Further, the magnitude of the second force F_(b) may be determined,in part, by the angular frequency w and the moment of inertia of secondmass member 120 b. Each member of the first mass member 120 a may have adifferent mass or may share a common first mass, and each member of thesecond mass member 120 b may have a different mass or may share a commonsecond mass. In an embodiment, the first and second masses may beapproximately equal. In this case, force F_(a) would have a similarmagnitude to force F_(b), irrespective of respective angular positionsof first and second mass members. Counter rotation of the first shaft105 a and second shaft 105 b at angular frequency w may yield aresultant force F=F_(a)+F_(b) that is maximal at an angular position inwhich a tangential velocity of first mass member 120 a and a tangentialvelocity of second mass member 120 b are substantially collinear andoriented in the same direction. Further, the resultant force F mayvanish at an angular position in which the tangential velocity of firstmass member 120 a and the tangential velocity of second mass member 120b are substantially collinear and oriented in substantially oppositedirections. In an embodiment, the amplitude of the time-dependentresultant force F may have a value of about 89000 N for an angularfrequency ω of about 183 rad/s.

In some embodiments, mass members in first mass member 120 a may beembodied as respective first slabs disposed substantiallyperpendicularly to axis 102. Each of these first slabs may be elongatedand assembled to be substantially parallel to one another. Further, eachof these first slabs may be mounted eccentrically on the first shaft 105a. Similarly, mass members in second mass member 120 b may also beembodied as respective second slabs, also disposed substantiallyperpendicularly to axis 102. Each of the second slabs may also beelongated and assembled to be substantially parallel to one another. Inaddition, the second slabs may be mounted eccentrically on second shaft105 b.

The first slabs may each have a defined first mass and a defined firstsize, and the second slabs may also collectively share the defined firstmass and the defined first size. Accordingly, the magnitude of the forceF_(a) and the magnitude of the force F_(b) may be essentially equalirrespective of the respective angular positions of the first slabs andthe second slabs. As mentioned, the counter rotation of first shaft 105a and second shaft 105 b at angular frequency ω may yield a resultantforce F=F_(a)+F_(b) that is maximal at an angular position in which thetangential velocity of the first slabs and the tangential velocity ofthe second slabs are substantially collinear and oriented in the samedirections. Likewise, the resultant force F may be substantially zero(or otherwise negligible) at an angular position in which the tangentialvelocity of the first slabs and the tangential velocity of the secondslabs are substantially collinear and oriented in substantially oppositedirections.

In some embodiments, as shown in FIG. 1, first mass member 120 a isassembled in proximity to and spatially separated along axis 102 fromsecond mass member 120 b. At an angular position in which the tangentialvelocity of first mass member 120 a and the tangential velocity ofsecond mass member 120 b are substantially collinear and oriented insubstantially opposite directions, forces F_(a) and F_(b) describedherein may not cancel one another completely due to imperfect alignmentbetween first mass member 120 a and second mass member 120 b, asdescribed in more detail below.

Incomplete cancellation of the forces may result in residual net forcesthat are oriented along a direction that is transverse to thelongitudinal axis 102. For example, the residual net forces may beoriented along the x direction of the Cartesian coordinate system shownin FIG. 1. The spatial offset between mass members 120 a and 120 b andthe residual net forces form a couple, which may distort the linearvibration generated by the eccentric vibrator apparatus 100. In order toremove or reduce such a couple, first counterbalance mass member 130 aand second counterbalance mass member 130 b are added to eccentricvibrator apparatus 100, as described above. As is illustrated in FIGS. 1and 2, for example, first counterbalance mass member 130 a and secondcounterbalance mass member 130 b also are offset relative to oneanother, along the longitudinal axis 102. Therefore, due to this spatialoffset, counterbalance mass members 130 a and 130 b also generate anadditional couple as a result of incomplete cancellation of forcesgenerated by these mass members. By aligning counterbalance mass members130 a and 130 b in a transverse direction opposite the transversedirection along which mass members 120 a and 120 b are oriented, asshown in FIG. 2, for example, the couple resulting from the counterrotation of the counterbalance mass members 130 a and 130 b may cancelthe couple generated by the mass members 120 a and 120 b.

In some embodiments, mass members in first counterbalance mass member130 a may share a common first mass, and mass members in secondcounterbalance mass member 130 b may share a common second mass. Amagnitude of masses 130 a and 130 b may therefore be essentially equal.The magnitude of the first and second masses of counterbalancing massmembers 130 a and 130 b may be configured to be less than the net massof mass members 120 a and 120 b, due to differences in spatial offsets,as needed to cancel unwanted residual couple from interaction of massmembers 120 a and 120 b.

As is illustrated in FIG. 1, first mass member 120 a and firstcounterbalance mass member 130 a may be assembled to have an offsetrelative angular alignment. In addition, second mass member 120 b andsecond counterbalance mass member 130 b may also be assembled to havethe same relative alignment offset. The relative alignment offset may beindicated by an angle θ (a real number in suitable units, such asradians or degrees) between a line representative of the orientation offirst mass member 120 a and another line representative of theorientation of first counterbalance mass member 130 a.

In an embodiment in which θ is essentially equal to π (or 180 degrees),as is illustrated in FIG. 2, for example, the resultant force F, due tomasses 120 a and 120 b, may be oriented substantially opposite to theresultant force F′ due to masses 130 a and 130 b. As such, a netresidual couple force is essentially zero when masses 120 a and 120 bare not aligned. Thus, first counterbalance mass member 130 a and/orsecond counterbalance mass member 130 b may be utilized to maintainlinearity of the vibrational motion produced by the eccentric vibratorapparatus 100 when shafts 105 a and 105 b are counter rotating, asdescribed in greater detail below with reference to FIGS. 11 to 14.

With further reference to FIG. 1, eccentric vibrator apparatus 100includes a first rotor mechanism 140 a that generates rotation of thefirst shaft 105 a. Vibrator apparatus 100 also includes a second rotormechanism 140 b that generates rotation of second shaft 105 b. In someembodiments, first rotor mechanism 140 a may include a first rotorassembly (not shown) mechanically coupled to first shaft 105 a, and afirst stator assembly (not shown) electromagnetically coupled to thefirst rotor assembly. First rotor mechanism 140 a may also include afirst bearing assembly (not shown) mechanically coupled to first shaft105 a near first mass member 120 a, and may further include a secondbearing assembly (not shown) mechanically coupled to first shaft 105 anear first counterbalance mass member 130 a. Further, second rotormechanism 140 b may include a second rotor assembly (not shown)mechanically coupled to second shaft 105 b, and a second stator assembly(not shown) electromagnetically coupled to the second rotor assembly.Second rotor mechanism 140 b may also include a first bearing assembly(not shown) mechanically coupled to second shaft 105 b near second massmember 120 b, and may further include a second bearing assembly (notshown) mechanically coupled to second shaft 105 b near secondcounterbalance mass members 130 b.

In some embodiments, first rotor mechanism 140 a may include a firstfeedback device such as an encoder device (not shown) attached to firstshaft 105 a. The first feedback device may provide one or more of firstinformation indicative of a respective position of at least one massmember of first mass member 120 a; second information indicative of theangular velocity ω of the first shaft 105 a; or third informationindicative of a rotation direction (such as clockwise direction orcounterclockwise direction) of the first shaft 105 a. A position offirst mass member 120 a is represented by an angle between 0 and 2π perrevolution of the first shaft 105 a, relative to a defined origincorresponding to a particular placement of the first shaft 105 a. Rotormechanism 140 b may further include a second feedback device such as anencoder device (not shown) attached to second shaft 105 b.

The second feedback device may provide one or more of first informationindicative of a respective position of second mass member 120 b; secondinformation indicative of angular velocity ω of second shaft 105 b; orthird information indicative of a rotation direction of second shaft 105b. A position of second mass member 120 b is represented by an anglebetween 0 and 2π per revolution of second shaft 105 b, relative to adefined origin corresponding to a particular placement of the firstshaft 105 b.

First feedback device and second feedback device may be embodied asrespective encoder devices. Each of the respective encoder devices maybe embodied in or may include, for example, a rotary encoder device. Arotary encoder device may include, for example, a 1024pulse-per-rotation rotary encoder device. An encoder device may includean essentially circular plate that rotates with the shaft (either thefirst shaft 105 a or second shaft 105 b).

The essentially circular plate may include openings alternating withsolid sections. The openings and solid section partition the plate inmultiple arcs of essentially equal length, subtending a defined angleΔy. The greater the number of openings in the encoder device, thesmaller the value of Δy, and thus, the greater the angular positionresolution of the encoder device. Each opening may represent a value ofan angular position of the shaft. The encoder device may also include,for example, a light source device, a first sensor, and a second sensor.The light source device may illuminate the essentially circular plate,causing the first light sensor to provide an electric signal in responseto being illuminated and further causing the second light sensor toprovide another electric signal in response to being obscured by a solidsection. As the shaft rotates, the first sensor and the second sensorprovide respective trains of pulses that may be utilized to determinethe angular velocity of the shaft, an angular position of the shaft,and/or a direction of rotation of the shaft. The disclosure is notlimited to rotary encoder devices and other types of encoder devices maybe utilized in various embodiments.

By controlling respective initial angles of rotation of first shaft 105a and rotation of second shaft 105 b—and, thus, controlling a relativeangle offset between such shafts—a direction of a resultant forcegenerated by first mass member 120 a and of second mass member 120 b maybe controlled. As such, a resultant force directed in a required orintended direction perpendicular to the axis 102 may be achieved byconfiguring and maintaining initial angles of, and associated relativeangle offset between, the respective substantially circular motions ofthe first shaft 105 a and second shaft 105 b. Configurations of suchinitial angles may be performed during operation (with the mass memberin movement) or at start up (with the mass members at rest) of theeccentric vibrator apparatus.

FIGS. 3A and 3B show isometric views of an eccentric vibrator apparatus300 in accordance with an embodiment of the disclosure. Vibratorapparatus 300 of FIG. 3A includes a housing assembly that is elongatedalong an axis 302. The housing assembly includes a first assembly 330and a second assembly 360. First assembly 330 may house a first motorassembly (for example, motor assembly 110 a of FIG. 1) and secondassembly 360 may house a second motor assembly (for example, motorassembly 110 b of FIG. 1). First assembly 330 may include a first motorcase 335, a first cover plate 340 (which may be a junction box cover insome embodiments), and a first cover assembly 345. The first motorassembly (e.g., motor assembly 110 a of FIG. 1) may be placed withinfirst motor case 335. Second assembly 360 includes a second motor case365, a second cover plate 370 (e.g., a junction box cover), and a secondcover assembly 375. The second motor assembly (for example, motorassembly 110 b of FIG. 2) may be placed within second motor case 365.Various materials may be utilized to manufacture first assembly 330 andsecond assembly 360. For example, any rigid material may be utilized,such as a metal (for example and without limitation, aluminum), aferrous alloy (for example and without limitation, stainless steel), anon-ferrous alloy, another type of metallic alloy, etc. In otherembodiments, a plastic may be utilized depending on the application(e.g., for consumer electronics).

As is illustrated in FIG. 3A, first motor case 335 includes a flangemember 350 that has multiple openings that are configured to receiverespective first fastening members. Similarly, second motor case 365also includes a flange member 380 that also has multiple openingsconfigured to receive respective second fastening members. The firstfastening members and the second fastening members may respectively mateto allow assembly of first motor case 335 and second motor case 365 intoa single unit via flange member 350 and flange member 380.

First motor case 335 may also include second flange members 355, havingone or more openings configured to receive respective one or morefastening members. Second motor case 365 may also include second flangemembers 385, having one or more openings configured to receiverespective one or more fastening members. Second flange members 355 and385, along with the one or more fastening members in each one of thefirst motor case 335 and second motor case 365 may be configured tocouple eccentric vibrator apparatus 300 to equipment. As mentioned,vibrator apparatus 300 may be coupled to industrial equipment, userequipment, consumer electronics, etc., to thereby generate vibrationalmotion in such equipment

FIG. 4 illustrates an exploded view of eccentric vibrator apparatus 300of FIGS. 3A and 3B, in accordance with one or more embodiments of thedisclosure. As described above with reference to FIGS. 3A and 3B,eccentric vibrator apparatus 300 includes a first housing assembly withfirst motor case 335, first cover plate 340, and first cover assembly345. Eccentric vibrator apparatus 300 also includes a second housingassembly with second motor case 365, second cover plate 370, and secondcover assembly 375. Eccentric vibrator apparatus 300 also includes afirst motor assembly and a second motor assembly, such as first motorassembly 110 a and second motor assembly 110 b of FIGS. 1 and 2. Partsincluded in such assemblies may form an arrangement that has inversionsymmetry with respect to a plane that essentially bisects the eccentricvibrator apparatus 300, the plane being normal to a longitudinal axisalong which the eccentric vibrator apparatus is aligned.

In this example, first motor assembly of the eccentric vibratorapparatus 300 may include a fan 408 a; a motor end cover 410 a; anencoder mounting ring 412 a; an encoder 414 a; and a first plurality of(counterbalance, or outboard) mass members 415 a. The first motorassembly may also include a first bearing assembly having a seal housing416 a, a shaft seal 418 a, a shaft seal ring 420 a, a first (outboard)bearing 422 a, and a first (outboard) bearing housing assembly 424 a.The first motor assembly may further include a seal housing 426 a; anadditional shaft seal 428 a; a stator assembly 430 a; and a rotorassembly 432 a.

The first motor assembly may still further include a second bearingassembly having a seal housing 434 a, an additional shaft seal 436 a, asecond (inboard) bearing housing assembly 438 a, a second (inboard)bearing 440 a, a seal housing 442 a, a shaft seal ring 444 a, and anadditional shaft seal 446 a. The first motor assembly may also include asecond mass member, including a mass member 448 a and a second massmember 450 a. While the second mass member is illustrated as having twomass members, the disclosure is not so limited. In further embodiments,more than two mass members or fewer than two mass members may beassembled. The first motor assembly may still further include a firstshaft 460 a oriented along the longitudinal axis 302 of the eccentricvibrator apparatus 300.

The second motor assembly of the eccentric vibrator apparatus 300 mayinclude a fan 408 b; a motor end cover 410 b; an encoder mounting ring412 b; an encoder 414 b; and a first plurality of (counterbalance, oroutboard) mass members 415 b. The second motor assembly may also includea first bearing assembly having a seal housing 416 b, a shaft seal 418b, a shaft seal ring 420 b, a first (outboard) bearing 422 b, and afirst (outboard) bearing housing assembly 424 b. The second motorassembly may further include a seal housing 426 b; an additional shaftseal 428 b; a stator assembly 430 b; and a rotor assembly 432 b. Thesecond motor assembly may still further include a second bearingassembly having a seal housing 434 b, an additional shaft seal 436 b, asecond (inboard) bearing housing assembly 438 b, a second (inboard)bearing 440 b, a seal housing 442 b, a shaft seal ring 444 b, and ashaft seal 446 b. The second motor assembly may also include a secondmass member, including a mass member 448 b and a mass member 450 b.While the second mass member is illustrated as having two mass members,the disclosure is not so limited. In further embodiments, more than twomass members or fewer than two mass members may be assembled. The secondmotor assembly may still further include a second shaft 460 b orientedalong the longitudinal axis 302 of the eccentric vibrator apparatus 300.

FIG. 5 is a cross-sectional view of eccentric vibrator apparatus 300 ofFIGS. 3A, 3B, and 4, in accordance with one or more embodiments of thedisclosure. As is illustrated, first plurality of (counterbalance, oroutboard) mass members 415 a is assembled to have an alignment offset ofabout π relative to mass members 448 a and 450 a. First plurality of(counterbalance) mass members 415 b is assembled to have an alignmentoffset θ′ of about −π relative to 448 b and 450 b. Further, alignmentoffset θ′ between (i) the second mass member that includes mass members448 a and 450 a, and (ii) the second mass member that includes massmembers 448 b and 450 b may be adjustable. As such, an alignment offsetθ′ of about π that is shown in FIG. 5 is illustrative and other offsetsmay be configured.

FIG. 6A is a side view of vibratory system 600 that utilizes eccentricvibrator apparatus 300, in accordance with one or more embodiments ofthe disclosure. Vibratory system 600 includes a deck assembly 610 thatis mechanically coupled to eccentric vibrator apparatus 300 by, forexample, coordinated flange members and fastening members (e.g., flangemembers 355 and 385 of FIGS. 3A and 3B). During operation, eccentricvibrator apparatus 300 may generate a time-dependent force f(t). Thus,in operation, eccentric vibrator apparatus 300 may exert atime-dependent oscillatory force f(t) on the deck assembly 610, causinga time-dependent oscillatory mechanical motion of the deck assembly 610.The intensity and period of oscillation of the mechanical motion may bedetermined by the angular frequency ω of rotation of shafts in theeccentric vibrator apparatus 300 and by other mechanical parametersincluding moments of inertia.

An amplitude of time-dependent force f(t) may be determined, in part, bythe angular velocity ω of the shafts in eccentric vibrator apparatus300, by the respective resultant moments of inertia of a first massmember and a second mass member in the eccentric vibrator apparatus 300,and by the respective moments of inertia of a first counterbalance massmember and a second counterbalance mass member in eccentric vibratorapparatus 300. The time-dependent force f(t) may be oriented in adirection substantially perpendicular to the longitudinal axis ofeccentric vibrator apparatus 300 (e.g., axis 102 in FIG. 1). As such,the time-dependent force f(t) may be represented as a three-dimensionalvector (f_(x)(t), f_(y)(t), f_(z)(t)), where the vector componentf_(z)(t) may be substantially null and the time dependent force f(t) maybe substantially equal to (f_(x)(t), f_(y)(t), 0). In an examplescenario in which the deck assembly 610 starts at rest and eccentricvibrator apparatus 300 is energized from an power-off state, f(t) mayself-align, after a transient period (for example, about 500 ms), into adirection that passes through the position of a center of gravity (CG)620 of the deck assembly, in the x-y plane.

Such a self-alignment may occur based on angular momentum conservationin vibratory system 600 after eccentric vibrator apparatus 300 isenergized. Such alignment may be configured by choice of motor assembly,such as an assembly that includes an asynchronous motor (such as aninduction motor) that allows slip between an input frequency and shaftspeed. Such a motor may thereby produce torque without reliance onphysical electrical connections to a rotor. Accordingly, an angle ϕindicative of the orientation of the time-dependent force f(t) relativeto a base side of the deck assembly 610 may be determined by theposition of the eccentric vibrator apparatus 300 on the deck assembly610, along the x direction in the coordinate system illustrated in FIG.6A.

While the f(t) is illustrated as being strictly collinear with a linehaving an orientation ϕ, the actual f(t) generated by eccentric vibratorapparatus 300 traverses, over time, an ellipse having a semi-major axisparallel to the line having orientation ϕ and a semi-minor axis that ismuch smaller (such as one, two, or three orders of magnitude smaller)than the semi-major axis. Such an ellipse may be referred to as a “tightellipse.” Specifically, angle ϕ decreases as the coordinate of theeccentric vibrator apparatus 300 along the x axis increases (or, morecolloquially, as the eccentric vibrator is moved forward on the deckassembly) and increases as the coordinate of the eccentric vibratorapparatus 300 along the x axis decreases (or as the eccentric vibratoris moved rearward). Angle ϕ and the magnitude |f(t)| may determine therespective magnitudes of vector components f_(x)(t) and f_(y)(t). Forexample, small ϕ (that is, a few degrees) may yield a large f_(x)(t) anda small f_(y)(t), whereas large ϕ (for example, several tens of degrees)may yield a small f_(x)(t) and a large f_(y)(t). Thus, the angle ϕ mayadjusted to control a conveyance rate or residence time of particulatematter or other types of solids on an x-z plane of deck assembly 610.

Various mechanisms may be used to secure eccentric vibrator apparatus300 on deck assembly 610. For example, as is illustrated in FIG. 6B, afastening mechanism 650 may include a rail or another type of trackmechanism that may permit moving the eccentric vibrator apparatus alongthe x axis. Fasteners, such as clamps, bolts, etc., may be used tosecure eccentric vibrator apparatus 300 at a position along the x axis.Fastening mechanism 650 may allow eccentric vibrator apparatus 300 to beplaced at various positions along deck assembly 610. Fastening mechanism650 may include another type of rail or track mechanism that includesmultiple locking mechanisms to secure eccentric vibrator apparatus 300at preset positions along the x axis. For example, as is shown in FIG.6B, defined positions may include positions x₁, x₂, x₃, x₄, x₅, x₆, x₇,x₈, and x₉, where respective locking mechanisms are configured. Thedisclosure is, of course, not limited to nine preset positions and morethan nine positions or fewer than nine preset positions may beimplemented. In some embodiments, multiple locking mechanisms mayinclude one or more sawtooth members configured to engage other lockingmechanisms included in a bottom surface of eccentric vibrator apparatus300. In other embodiments, multiple locking mechanisms may includerespective openings (threaded or otherwise) that may receive respectivebolts that may mate with respective nuts to secure the eccentricvibrator apparatus at preset positions.

FIGS. 7A and 7B are perspective views of an example vibratory systemthat utilizes an eccentric vibrator apparatus 710, in accordance withone or more embodiments of the disclosure. As is illustrated, eccentricvibrator apparatus 710 is mounted in a deck assembly 720 of separatorequipment.

In some embodiments, an orientation of oscillation and a magnitude ofthe resultant force exerted by an eccentric vibrator apparatus may beconfigured without reliance on changes to the position at which theeccentric vibrator apparatus is mounted. In this regard, a controlsystem may be functionally coupled to eccentric vibrator apparatus 710to control motion of mass members and shafts included in eccentricvibrator apparatus 710.

FIG. 8 is a diagram of a vibratory system 800 that includes a controlsystem functionally coupled to eccentric vibrator apparatus 300, inaccordance with one or more embodiments of the disclosure. The controlsystem includes one or more operator interface devices 830 and one ormore motion controller devices 810. Vibratory system 800 also includesone or more power sources 820 that may energize the motor assembliesincluded in eccentric vibrator apparatus 300 and/or at least one deviceof the control system. Power source(s) 820 may include one or more powersupplies and/or a utility power source. Operator interface device(s) 830may include input/output (I/O) interface device(s), such as a humanmachine interface (HMI), which may allow selection of a desired mode ofvibration (for example, substantially linear excitation or substantiallyelliptical or circular excitation).

Operator interface device(s) 830 may further allow real-time monitoringor intermittent monitoring at particular instants. A mode of vibrationmay include a defined orientation and a defined magnitude of atime-dependent force f(t) exerted by eccentric vibrator apparatus 300.The defined orientation is represented by an angle α in FIG. 8. As isillustrated, α=0 would correspond to a time-dependent force f_(∥)(t)essentially aligned along an x direction. Stated differently, f₈₁(t) isessentially parallel to a base side of the of deck assembly 610. As isfurther illustrated, α=π/2 would correspond to a time-dependent forcef_(⊥)(t) that is essentially vertical, along a y direction, wheref_(⊥)(t) is essentially perpendicular to the base side of the of deckassembly 610.

Configuration of a mode of operation may include the configuration of adefined angular frequency of rotation of a shaft of eccentric vibratorapparatus 300 and/or the configuration of a defined angular offsetbetween a first eccentric mass member of a first motor assembly and asecond eccentric mass member of a second motor assembly. An operatorinterface device 830 may receive input information indicative of adesired angle α, angular frequency ω, and/or angular offset. The inputinformation may be used to configure a motion controller device 810 tocontrol vibratory motion of eccentric vibrator apparatus 300. While theresultant f(t) generated by eccentric vibrator apparatus 300 isillustrated as being linear with an orientation α, the actual f(t)generated by eccentric vibrator apparatus 300 traverses, over time, anellipse having a semi-major axis parallel to the line having the slope αand a semi-minor axis that is much smaller (for example, one, two, orthree orders of magnitude smaller) than the semi-major axis.

Depending on desired screen performance, angle a (which may also bereferred to as tight-ellipse angle) may be configured to induce slowconveyance of material to be screened, to thereby maximize dischargedryness. Alternatively, angle a may be configured to induce fastconveyance to material to be screened, to thereby increase machinehandling capacity, or may be configured to momentarily reverseconveyance of material to thereby dislodge stuck particles (i.e., forde-blinding).

Further, angle a may be adjusted during operation, as described herein,to an angle α′ of about 90° for a defined period of time to attaintemporary deblinding of a screen in a screening apparatus. After thedefined period, α′ of about 90° may be readjusted to α. Furthertemporary changes to a mode of operation may be implemented in variousembodiments. In one example, a transition from an angle α₀ of about 45°to angle α′ of about 60° may be made to slow conveyance and to cause adrier discharge from a slurry fed into a deck assembly having eccentriclinear vibrator 300. Subsequently, a transition from α′ of about 60° toα₀ of about 45° may be implemented to resume faster conveyance. Inanother example, an angle α of approximately 45° may be adjusted duringoperation, as described herein, to an angle α′ of about 30° for adefined period of time to remove accumulated matter on a screen. Afterthe defined period of time, α′ of about 30° may be readjusted to α.

Such an adjustment may be desirable in operation of a screening machineto screen a slurry. During screening, slurry material transforms from aliquid-solid mixture to a dewatered solid. Angle α may be adjusted toincrease dryness. For example, if the angle α is increased from about45° to approximately 60°, as described above, a flow rate of thematerial on the screening decreases. This decrease in flow rate permitsmore time for liquid to be driven out of the slurry as the materialmoves more slowly towards a discharge end of the screening machine.

FIG. 9 is a schematic illustration of a system that may include motioncontroller device(s) 810, a controller device 920, and drive devices930. Controller device 920 may be embodied in or may include aprogrammable logic controller (PLC), a microcontroller, etc., and drivedevices 930 may be embodied in or may include electronic motor drives,variable frequency drives (VFDs), etc. Controller device 920 may receiveinformation indicative of position, velocity of eccentric mass members,and/or of direction of rotation of eccentric vibrator apparatus 300.Controller device 920 may control drive devices 930 to generate aspecific mode of operation. In this regard, feedback devices 910 may becoupled to respective shafts of eccentric vibrator apparatus 300 and mayprovide first information indicative of respective positions of massmembers.

Feedback devices 910 may also provide second information indicative ofrespective angular velocities of the shafts. Feedback devices 910 mayprovide third information indicative of a direction of rotation of ashaft of eccentric vibrator apparatus 300. In one embodiment, the firstinformation, the second information, and the third information may beprovided directly to controller device 920. In another embodiment, thefirst information, the second information, and the third information maybe provided indirectly to controller device 920, where such informationis provided to respective drive devices 930, and relayed by drivedevices 930 to controller device 920. Controller device 920 may controldrive devices 930 to generate rotational movement of at least one of thecollinear shafts of eccentric vibrator apparatus 300.

Feedback devices 910 may include a first feedback device (such as afirst encoder device) attached to a first shaft of eccentric vibratorapparatus 300. The first feedback device may send one or more of (a)first information indicative of a respective position of at least one offirst mass members of eccentric vibrator apparatus 300, (b) secondinformation indicative of angular velocity of the first shaft, or (c)third information indicative of a direction of rotation of the firstshaft. Feedback devices 910 may also include a second feedback device(such as a second encoder device) attached to a second shaft of vibratorapparatus 300. The second feedback device may send one or more of (a)fourth information indicative of a respective position of at least oneof second mass members of eccentric vibrator apparatus 300, (b) fifthinformation indicative of angular velocity of the second shaft, or (c)sixth information indicative of direction of rotation of the secondshaft.

Controller device 920 may further receive the first information, thesecond information, the third information, the fourth information, thefifth information, the sixth information, and operator interface device830 information and may direct drive devices 930 to configure rotationalmovement of the first shaft and second shaft based at least on thereceived information. In an embodiment, controller device 920 mayreceive such information directly from the first feedback device and thesecond feedback device. In another embodiment, controller device 920 mayreceive the first information, the second information, the thirdinformation, the fourth information, the fifth information, and/or thesixth information indirectly, where such information is provided todrive devices 930, and relayed by drive devices 930 to controller device920.

Drive devices 930 may include a first drive device coupled to a firstmotor assembly including the first shaft of eccentric vibrator apparatus300. Controller device 920 may direct the first drive device to generatethe rotational movement of the first shaft based on one or more of aportion of the first information; a portion of the second information; aportion of the third information and operator interface device 830information. Drive devices 930 may also include a second drive devicecoupled to a second motor assembly including the second shaft ofeccentric vibrator apparatus 300. Controller device 920 may direct thesecond drive device to configure the rotational movement of the secondshaft based on one or more of a portion of the fourth information; aportion of the fifth information; a portion of the sixth information andoperator interface device 830 information.

FIG. 10A is a schematic illustration of an eccentric vibrator apparatus1000 coupled to a control system, in accordance with one or moreembodiments of the disclosure. As illustrated in FIG. 10A, system 1000may include a controller device 1010 that may be embodied in or mayinclude a programmable logic controller. In addition, drive devices 930(e.g., see FIG. 9) may be embodied in or may include a first electronicmotor drive 1020A and a second electronic motor drive 1020B. Thedisclosure is not limited to electronic motor drives that share a commonarchitecture. First electronic motor drive 1020A and second electronicmotor drive 1020B may power respective motor assemblies in eccentricvibrator apparatus 300. In this regard, first electronic motor drive1020A may include an electronic inverter or another type of power supplycoupled (for example, electromechanically coupled) to a first motorassembly by, for example, a power line assembly 1060A. Second electronicmotor drive 1020B may include an electronic inverter or another type ofpower supply coupled to a second motor assembly by a second power lineassembly 1060B.

First and second power line assemblies 1060A and 1060B may include, forexample, an electrical conductor, power connectors, insulating coatings,etc. First electronic motor drive 1020A and second electronic motordrive 1020B may be coupled to respective power lines 1030A and 1030Bthat are connected to a utility power source (such as a 50 Hz AC powersource or a 60 Hz AC power source). Further, first electronic motordrive 1020A may be coupled (electrically or electromechanically) to thefirst feedback device of eccentric vibrator apparatus 300 by a first bus1070A. Second electronic motor drive 1020B may also be coupled(electrically or electromechanically) to a second bus 1070B. First andsecond bus structures 1070A and 1070B allow transmission of information(analog and/or digital) that may represent angular position, angularvelocity, and/or direction of rotation of a shaft of eccentric vibratorapparatus 300. The disclosure is not limited to buses that share acommon architecture.

As is further illustrated in FIG. 10A, system 1000 may further includeoperator interface device(s) 830 and remote operator interface device(s)1080. Operator interface device(s) 830, programmable logic controller1010, first electronic motor drive 1020A, and second electronic motordrive 1020B may be coupled by network devices 1050 (such as a high-speednetwork device or bus). Network devices 1050 may allow exchange ofinformation (for example, data and/or signaling) between operatorinterface device(s) 830, programmable logic controller 1010, firstelectronic motor drive 1020A, and second electronic motor drive 1020B.One or more of remote operator interface device(s) 1080 may be coupledto a network device 1050 via wireless links and/or wired links 1085.Device(s) 1080 may allow configuration and/or monitoring of operation ofeccentric vibrator apparatus 300.

FIG. 10B is a schematic illustration of a vibratory system 1090 having acontrol system that is functionally coupled to other types of eccentricmotors to thereby control a type of motion generated by the eccentricmotor. For example, a control system may be functionally coupled toconventional eccentric motors 1095 a and 1095 b, such as eccentricmotors that do not include collinear shafts. A mode of rotation (forexample, magnitude of angular velocity and direction of rotation) ofeach one of the conventional motors 1095 a and 1095 b may be controlledindependently, according to an embodiment. For example, to generate anessentially linear mechanical excitation, a PLC 1010 may direct a firstelectronic motor drive 1020A to cause eccentric motor 1095 a to rotatein a first direction at an angular velocity ω. PLC 1010 may furtherdirect a second electronic motor drive 1020B to cause eccentric motor1095 b to rotate in a second direction opposite the first direction, atthe angular velocity ω. In another example, to generate an essentiallycircular mechanical excitation, PLC 1010 may direct first electronicmotor drive 1020A to cause eccentric motor 1095 a to rotate in a firstdirection at an angular velocity ω. PLC 1010 may further direct secondelectronic motor drive 1020B to cause eccentric motor 1095 b to rotatein the first direction as well, at the angular velocity ω.

As described above, control system that includes motion controllerdevice(s) 810 (e.g., see FIG. 8) may generate a predetermined mode ofoperation of a disclosed eccentric vibrator apparatus. The controlsystem may configure and/or monitor the respective movements—such asrespective angular velocities and angular positions—of collinear shaftsincluded in the eccentric vibrator apparatus independently andcontinuously, nearly continuously, or at specific times (for example,periodically, nearly periodically, or according to a schedule). Forexample, a mode of operation may be monitored and/or configured asdesired in nearly real time (or essentially periodically, at timeintervals significantly shorter than, such as a hundredth part, athousandth part, a millionth part, and so forth, of a period ofrevolution 1/ω of a shaft of the apparatus) without powering off theeccentric vibrator apparatus. In this regard, motion controllerdevice(s) 810 may employ various techniques, including electronicgearing to configure the angular velocity and/or angular position of ashaft during operation of the eccentric vibrator apparatus, withoutneeding to power down the eccentric vibrator apparatus to perform areconfiguration operation.

As described above, the control system may be configured to set andmaintain a relative angle offset between respective rotational movementsof collinear shafts of an eccentric vibrator apparatus. In this regard,the control system may impose respective initial angles of respectiverotational movements of the collinear shafts. The respective initialangles may be defined relative to a reference coordinate system and maydetermine an orientation of oscillation of a resultant force f(t) (anessentially sinusoidal force) produced by the eccentric vibratorapparatus. The orientation may be represented by an angle relative to adefined direction in a reference coordinate system. For example, thereference coordinate system may be a Cartesian system having an axis(for example, a z-axis as shown in FIG. 8) essentially parallel to thelongitudinal axis of the eccentric vibrator apparatus. A directionrepresenting an orientation of the oscillation of the resultant forcef(t) may lie in a plane (e.g., in the x-y of FIG. 8) that is normal tothe z axis.

FIGS. 11-14 illustrate schematic force diagrams for four respectiveconfigurations of initial angles and associated relative angle offsets,at nine different instants during operation of an eccentric vibratorapparatus 1100 in accordance with embodiments described herein.

FIG. 11 illustrates force configurations at instants t₀, t₁, t₂, t₃, t₄,t₅, t₆, t₇, and t₀+T for initial angles equal to 0 for both collinearshafts in eccentric vibrator apparatus 1100, resulting in a relativeangle offset essentially equal to 0. At any given instant, forces areindicated by arrows within the circle, and shaded regions indicatepositions of respective masses. Arrows external to the circle indicatevelocities. Forces corresponding to respective pluralities of massmember are represented with thin arrows, and resultant forces F arerepresented with thick arrows. In this example, angles are definedrelative to the Cartesian coordinate system shown in FIG. 11, and Trepresents a period of the rotation of the collinear shafts. For theinitial angular configuration and associated relative angle offset ofthis example, a first mass member of eccentric vibrator apparatus 1100may be essentially aligned with a second mass member at angles 0 and π,as is illustrated by the diagrams corresponding to t₀ and t₄.

At each instant, the force exerted by a given mass (e.g., shown by athin arrow in the circle) is essentially perpendicular to the velocity(e.g., shown by an arrow outside of the circle) of the mass members. Themasses generate forces that share a common magnitude. For example, afirst mass member and a second mass member may exert, respectively, aforce F_(a) and a force F_(b), where |F_(a)|=|F_(b)|. As shown in FIG.11, for initial angles essentially equal to 0, the resultant force f(t)may be oriented along the x direction, or parallel to a base of theeccentric vibrator apparatus 1100. Further, forces cancel at instants t₂and t₆ and point in the negative x direction at instant t₄. Theconfiguration of FIG. 11 therefore causes horizontal, side-to-sidevibration of equipment (such as a deck assembly or screen basket) ontowhich the force is exerted. For instance, a screen frame or deckassembly may vibrate with oscillations in a plane that is essentiallyhorizontal.

FIG. 12 illustrates a second mode of vibration in which a linearoscillation is oriented at an angle with respect to the horizontal, inaccordance with an embodiment of the disclosure. In this example, thecontrol system may momentarily delay the first shaft and momentarilyincrease speed of the second shaft of the eccentric vibrator apparatus,thus configuring respective initial angles of the first shaft and thesecond shaft that yield a relative angle offset approximately equal toπ/4 (set t₂ equal to t₀ in FIG. 12). In FIG. 12, one of the mass membersmay be advanced, for example, by π/4 and the other one of the massmembers may be delayed, for example, by π/4. Therefore, the first massmember may be essentially aligned with the second mass member at anglesπ/4 and 5π/4, as is illustrated by the diagrams corresponding to to7 andt₄. For such initial angles and associated relative angle offset, theresultant force f(t) may be oriented at about π/4 relative to the baseof the eccentric vibrator apparatus 1100.

FIG. 13 illustrates a third mode of vibration in which a linearoscillation is oriented at an angle with respect to the horizontal, inaccordance with an embodiment of the disclosure. By setting the initialangles of rotation of the first shaft and the second shaft to beapproximately 3π/4, a relative angle offset of about 3π/4 may beattained, as is shown in FIG. 13 (set t₂ equal to t₀ in FIG. 13). Inthis example, the first mass member may be essentially aligned with thesecond mass member at angles 3π/4 and 7π/4, as is illustrated by thediagrams corresponding to instants t₀ and t₄ in FIG. 13. Thus, rotatingthe orientation of oscillation of the resultant force f(t) by an angleπ/2 relative to the orientation for a relative angle offset of π/4 (seeFIG. 12), causing such a force to be essentially aligned with the otherdiagonal of the x-y plane of the Cartesian coordinate system relative tothe motion of FIG. 12.

FIG. 14 illustrates a fourth mode of vibration in which a linearoscillation is oriented at an angle with respect to the horizontal, inaccordance with an embodiment of the disclosure. The control system mayset the initial angles of respective rotations of the first shaft andthe second shaft to π/2, causing a relative angle offset ofapproximately π/2, as is shown in FIG. 14. In this example, a first massmember may be advanced, for example, by π/2 while a second mass membermay be advanced by π/2. As such, the first mass member may beessentially aligned with the second mass member at angles π/2 and 3π/2 ,as is illustrated by the diagrams corresponding to t₀ and t₄ in FIG. 14(t₁ equal to t₀ in FIG. 14). The oscillation of the resultant force f(t)may therefore be oriented essentially perpendicular to the horizontal(i.e., aligned along the y direction). As such, the motion isessentially a vertical, up-down vibration. In this mode of vibration, ascreen frame or deck assembly may be caused to vibrate with a linearoscillatory motion that is essentially perpendicular to the ground.

The control systems described herein may cause changes to angles ofrespective rotations of collinear shafts during the operation of aneccentric vibrator apparatus. In this regard, a plane of oscillatorymotion may be changed while the eccentric vibrator apparatus is running.In a different mode of operation, the vibratory motion may be changedfrom a linear oscillation to a circular or elliptical oscillation. Forexample, a control system may cause collinear shafts of an eccentricvibrator apparatus to rotate in a common direction and at a commonangular velocity to generate an essentially circular mechanicalexcitation. For example, while the system is generating linear motionwith counter rotating masses, the control system may change thedirection of rotation of a first shaft (or, in some instances, a secondshaft) of the substantially collinear shafts to be reversed. Upon such areversal, the control system may also cause the first shaft and thesecond shaft to be angularly aligned—neither the first shaft nor thesecond shaft is angularly advanced or angularly retarded relative to theother shaft. Thus, the substantially collinear shafts are configured torotate in a common direction at a common angular frequency ω, without anangular shift between the shafts, resulting in a substantially circularmotion of the eccentric vibrator apparatus. In further embodiments,elliptical as well as circular vibrations may be implemented with massesrotating in the same direction but with relative offsets.

In some embodiments, configuration of the substantially circular orelliptical motion may be implemented in response to actuation of abutton on an HMI or upon selection of a selectable visual elementdisplayed on a display device (which, in some embodiments, may beincluded in the HMI). The control of initial angles and ensuing relativeangle offsets during operation of the eccentric vibrator apparatus maypermit adjusting the orientation of a vibrating oscillation without aneed for unmounting and re-mounting of the eccentric vibrator apparatus,as would be the case with a conventional vibration device. As such,disclosed systems and methods provide improved efficiency and/orversatility of the vibrating system.

In further embodiments, an eccentric vibrator apparatus may generate asubstantially circular mechanical excitation, without reliance on acontrol system to configure circular motion and to provide power. Insuch embodiments, a direction of rotation of a shaft of the eccentricvibrator apparatus may be reversed by changing a polarity of two ofthree incoming power leads of a three-phase asynchronous induction motorthat generates rotation of the shaft. For example, a three-phase systemmay include (i) a first line power L1, a second line power L2, and athird power line L3, and (ii) a first motor terminal T1, a second motorterminal T2, and a third motor terminal T3. Clockwise rotation of ashaft may be accomplished by connecting L1 to T1, L2 to T2, and L3 toT3. Alternatively, counterclockwise rotation of the shaft may beachieved by switching L1 to be connected to T3, maintaining L2 connectedto T2, and switching L3 to be connected to T1.

A control system may allow real-time or nearly real-time control ofmotor assembly speed and/or vibrating force direction. A rate at whichparticulate matter is conveyed from a feed end to a discharge end of aseparator system may, in turn, be controlled by controllingcharacteristics of an eccentric vibrator apparatus that is coupled tothe separator system. In addition to shaker systems, an eccentricvibrator apparatus may be coupled to feeders, such as vibratory feeders,where feed rate of material may be accurately controlled. As an example,in high-volume processing applications, conveyance rate may be increasedto move particulate matter or other types of solids away from ascreening surface and/or to expose a screening surface area to anincoming flow of matter. As another example, a conveyance rate may bedecreased to increase dryness of screened material by increasing aresidence time of the material on a screening surface.

FIG. 15 is a block diagram of an example computer system 1500 in whichdisclosed embodiments, or portions thereof, may be implemented ascomputer-readable code (i.e., machine-readable computer programinstructions), which is executed by one or more processors and causesthe one or more processors to perform operations of the disclosedembodiments, according to an embodiment.

Disclosed systems may include components implemented on computer system1500 using hardware, software, firmware, tangible computer-readable(i.e., machine-readable) media having computer program instructionsstored thereon, or a combination thereof, and may be implemented in oneor more computer systems or other processing system.

If programmable logic is used, such logic may be executed on acommercially available processing platform or a on a special purposedevice. One of ordinary skill in the art may appreciate that embodimentsof the disclosed subject matter can be practiced with various computersystem configurations, including multi-core multiprocessor systems,minicomputers, mainframe computers, computers linked or clustered withdistributed functions, as well as pervasive or miniature computers thatmay be embedded into virtually any device.

Various disclosed embodiments are described in terms of this examplecomputer system 1500. After reading this description, persons ofordinary skill in the relevant art will know how to implement disclosedembodiments using other computer systems and/or computer architectures.Although operations may be described as a sequential process, some ofthe operations may in fact be performed in parallel, concurrently,and/or in a distributed environment, and with program code storedlocally or remotely for access by single or multi-processor machines. Inaddition, in some embodiments the order of operations may be rearrangedwithout departing from the spirit of the disclosed subject matter.

As persons of ordinary skill in the relevant art will understand, acomputing device for implementing disclosed embodiments has at least oneprocessor, such as processor 1502, wherein the processor may be a singleprocessor, a plurality of processors, a processor in amulti-core/multiprocessor system, such system operating alone, or in acluster of computing devices operating in a cluster or server farm.Processor 1502 may be connected to a communication infrastructure 1504,for example, a bus, message queue, network, or multi-coremessage-passing scheme.

Computer system 1500 may also include a main memory 1506, for example,random access memory (RAM), and may also include a secondary memory1508. Secondary memory 1508 may include, for example, a hard disk drive1510, removable storage drive 1512. Removable storage drive 1512 mayinclude a floppy disk drive, a magnetic tape drive, an optical diskdrive, a flash memory, or the like. The removable storage drive 1512 maybe configured to read and/or write data to a removable storage unit 1514in a well-known manner. Removable storage unit 1514 may include a floppydisk, magnetic tape, optical disk, etc., which is read by and writtento, by removable storage drive 1512. As will be appreciated by personsof ordinary skill in the relevant art, removable storage unit 1514 mayinclude a computer readable storage medium having computer software(i.e., computer program instructions) and/or data stored thereon.

In alternative implementations, secondary memory 1508 may include othersimilar devices for allowing computer programs or other instructions tobe loaded into computer system 1500. Such devices may include, forexample, a removable storage unit 1516 and an interface 1518. Examplesof such devices may include a program cartridge and cartridge interface(such as that found in video game devices), a removable memory chip(such as EPROM or PROM) and associated socket, and other removablestorage units 1516 and interfaces 1518 which allow software and data tobe transferred from the removable storage unit 1516 to computer system1500.

Computer system 1500 may also include a communications interface 1520.Communications interface 1520 allows software and data to be transferredbetween computer system 1500 and external devices. Communicationsinterfaces 1520 may include a modem, a network interface (such as anEthernet card), a communications port, a PCMCIA slot and card, or thelike. Software and data transferred via communications interface 1520may be in the form of signals 1522, which may be electronic,electromagnetic, optical, or other signals capable of being received bycommunications interface 1520. These signals may be provided tocommunications interface 1520 via a communications path 1524.

In this document, the terms “computer program storage medium” and“computer usable storage medium” are used to generally refer to storagemedia such as removable storage unit 1514, removable storage unit 1516,and a hard disk installed in hard disk drive 1510. Computer programstorage medium and computer usable storage medium may also refer tomemories, such as main memory 1506 and secondary memory 1508, which maybe semiconductor memories (e.g., DRAMS, etc.). Computer system 1500 mayfurther include a display unit 1526 that interacts with communicationinfrastructure 1504 via a display interface 1528. Computer system 1500may further include a user input device 1530 that interacts withcommunication infrastructure 1504 via an input interface 1532. A userinput device 1530 may include a mouse, trackball, touch screen, or thelike.

Computer programs (also called computer control logic or computerprogram instructions) are stored in main memory 1506 and/or secondarymemory 1508. Computer programs may also be received via communicationsinterface 1520. Such computer programs, when executed, enable computersystem 1500 to implement embodiments as discussed herein. In particular,the computer programs, when executed, enable processor 1502 to implementthe processes of disclosed embodiments, such various stages in disclosedmethods, as described in greater detail above. Accordingly, suchcomputer programs represent controllers of the computer system 1500.When an embodiment is implemented using software, the software may bestored in a computer program product and loaded into computer system1500 using removable storage drive 1512, interface 1518, and hard diskdrive 1510, or communications interface 1520. A computer program productmay include any suitable non-transitory machine-readable (i.e.,computer-readable) storage device having computer program instructionsstored thereon.

Embodiments may be implemented using software, hardware, and/oroperating system implementations other than those described herein. Anysoftware, hardware, and operating system implementations suitable forperforming the functions described herein may be utilized. Embodimentsare applicable to both a client and to a server or a combination ofboth.

The disclosure sets forth example embodiments and, as such, is notintended to limit the scope of embodiments of the disclosure and theappended claims in any way. Embodiments have been described above withthe aid of functional building blocks illustrating the implementation ofspecified functions and relationships thereof. The boundaries of thesefunctional building blocks have been arbitrarily defined herein for theconvenience of the description. Alternate boundaries can be defined tothe extent that the specified functions and relationships thereof areappropriately performed.

The breadth and scope of embodiments of the disclosure should not belimited by any of the above-described example embodiments, but should bedefined only in accordance with the following claims and theirequivalents.

Conditional language, including terms such as “can,” “could,” “might,”or “may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainimplementations could include, while other implementations do notinclude, certain features, elements, and/or operations. Thus, suchconditional language generally is not intended to imply that features,elements, and/or operations are in any way required for one or moreimplementations or that one or more implementations necessarily includelogic for deciding, with or without user input or prompting, whetherthese features, elements, and/or operations are included or are to beperformed in any particular implementation.

The specification and annexed drawings disclose examples of systems andsystems that may provide configurable substantially eccentric mechanicalexcitations and/or substantially linear circular mechanical excitations.It is, of course, not possible to describe every conceivable combinationof elements and/or methods for purposes of describing the variousaspects of the disclosure, but it may be recognized that many furthercombinations and permutations of the disclosed elements are possible.Accordingly, various modifications may be made to the disclosure withoutdeparting from the scope or spirit thereof. In addition or in thealternative, other embodiments of the disclosure may be apparent fromconsideration of the specification and annexed drawings, and practice ofthe disclosure as presented herein. It is intended that the examples putforward in the specification and annexed drawings be considered, in allrespects, as illustrative and not restrictive. Although specific termsare employed herein, they are used in a generic and descriptive senseonly and not for purposes of limitation.

What is claimed is:
 1. An apparatus, comprising: a first shaft having afirst end and a second end; a second shaft having a third end and afourth end, wherein the first and second shafts share a common axis andthe first end and the third end are proximate to one another; a firstmass eccentrically mounted on the first shaft and configured to rotateabout the first shaft; a second mass eccentrically mounted on the secondshaft and configured to rotate about the second shaft; a third masseccentrically mounted on the first shaft at a first angle relative tothe first mass and configured to rotate about the first shaft; a fourthmass eccentrically mounted on the second shaft at a second anglerelative to the second mass and configured to rotate about the secondshaft, wherein the third and fourth masses are respectively spatiallyseparated from, and are configured to respectively act as partialcounterbalance masses to, the first and second masses; and a drivesystem configured to selectively generate elliptical, circular, andlinear vibratory motion such that: in a first selectable configuration,the drive system imparts rotational motion to the first and secondshafts to cause the first and second masses to rotate in a commondirection to thereby generate elliptical or circular vibratory motion ofthe apparatus; and in a second selectable configuration, the drivesystem imparts rotational motion to the first and second shafts to causethe first and second masses to rotate in opposite directions to therebygenerate linear vibratory motion of the apparatus.
 2. The apparatus ofclaim 1, wherein the drive system further comprises: a first motorassembly attached to the first shaft, the first motor assemblyconfigured to impart the rotational motion to the first shaft; and asecond motor assembly attached to the second shaft, the second motorassembly configured to impart the rotational motion to the second shaft.3. The apparatus of claim 1, further comprising: a control systemconfigured to control rotational frequencies, directions, and relativeangular positions of the first and second masses to thereby controllinear, elliptical, and circular vibratory motion of the apparatus. 4.The apparatus of claim 3, wherein the control system is furtherconfigured to control an angle of linear motion by controlling relativeangular positions of the first and second masses.
 5. The apparatus ofclaim 4, wherein the control system is further configured to change theangle of linear motion from a first angle to a second angle duringoperation of the apparatus.
 6. The apparatus of claim 3, wherein thecontrol system is further configured to change from linear motion toelliptical or circular motion during operation of the apparatus.
 7. Theapparatus of claim 3, wherein the control system is further configuredto control the first and second shafts to rotate in opposite directionswith a common frequency to generate linear vibrations.
 8. The apparatusof claim 3, wherein the control system is further configured to controlthe first and second shafts to rotate in a common direction with acommon frequency to generate circular vibrations.
 9. The apparatus ofclaim 3, further comprising: a measurement device that is configured tomeasure an angular position and/or a velocity of the first and secondmasses.
 10. The apparatus of claim 9, wherein the control system isfurther configured to control one or more of rotational frequencies,directions, and relative angular positions of the first and secondmasses based on measurements taken by the measurement device.
 11. Theapparatus of claim 3, wherein the control system is configured tocontrol the vibratory motion to be a linear motion along a line that isoriented at an angle in a range from approximately 0 radians toapproximately π radians relative to a fixed direction.
 12. The apparatusof claim 1, wherein: the first mass is mounted at or proximate to thefirst end of the first shaft and the third mass is mounted at orproximate to the second end of the first shaft; and the second mass ismounted at or proximate to the third end of the second shaft and thefourth mass is mounted at or proximate to the fourth end of the secondshaft.
 13. The apparatus of claim 1, wherein: the first and third massesare substantially in parallel, and the second and fourth masses aresubstantially in parallel.
 14. The apparatus of claim 1, wherein thefirst and second angles are each approximately 180 degrees.
 15. Aprocessor implemented method of controlling an apparatus that includes afirst shaft having a first end and a second end; a second shaft having athird end and a fourth end, wherein the first and second shafts share acommon axis and the first end and the third end are proximate to oneanother; a first mass eccentrically mounted on the first shaft andconfigured to rotate about the first shaft; a second mass eccentricallymounted on the second shaft and configured to rotate about the secondshaft; a third mass eccentrically mounted on the first shaft at a firstangle relative to the first mass and configured to rotate about thefirst shaft; and a fourth mass eccentrically mounted on the second shaftat a second angle relative to the second mass and configured to rotateabout the second shaft, wherein the third and fourth masses arerespectively spatially separated from, and are configured torespectively act as partial counterbalance masses to, the first andsecond masses; and a drive system configured to selectively generateelliptical, circular, and linear vibratory motion such that: in a firstselectable configuration, the drive system imparts rotational motion tothe first and second shafts to cause the first and second masses torotate in a common direction to thereby generate elliptical or circularvibratory motion of the apparatus; and in a second selectableconfiguration, the drive system imparts rotational motion to the firstand second shafts to cause the first and second masses to rotate inopposite directions to thereby generate linear vibratory motion of theapparatus, the method comprising: controlling, by a processor circuit,the drive system to select the first selectable configuration or thesecond selectable configuration.
 16. The method of claim 15, furthercomprising controlling, by the processor circuit, the drive system tocontrol an angle of linear motion by controlling relative angularpositions of the first and second masses.
 17. The method of claim 16,further comprising controlling, by the processor circuit, the drivesystem to change an angle of linear motion from a first angle to asecond angle during operation of the apparatus.
 18. The method of claim15, further comprising controlling, by the processor circuit, the drivesystem to change from linear motion to elliptical or circular motionduring operation of the apparatus.
 19. The method of claim 15, furthercomprising controlling, by the processor circuit, the drive system tocause the first and second shafts to rotate in opposite directions witha common frequency to generate linear vibrations.
 20. The method ofclaim 15, further comprising controlling, by the processor circuit, thedrive system to cause the first and second shafts to rotate in the samedirection with a common frequency to generate circular vibrations. 21.The method of claim 15, further comprising: monitoring a measurementdevice, by the processor circuit, to measure an angular position and/ora velocity of the first and second masses; and controlling, by theprocessor circuit, the drive system to control one or more of rotationalfrequencies, directions, and relative angular positions of the first andsecond masses, based on measurements taken by the measurement device.22. The method of claim 15, further comprising controlling, by theprocessor circuit, the drive system to control the vibratory motion tobe a linear motion along a line that is oriented at an angle in a rangefrom approximately 0 radians to approximately π radians relative to afixed direction.
 23. A method for controlling an eccentric vibrator thatincludes a first shaft having a first end and a second end; a secondshaft having a third end and a fourth end, wherein the first and secondshafts share a common axis and the first end and the third end areproximate to one another; a first mass eccentrically mounted on thefirst shaft and configured to rotate about the first shaft; a secondmass eccentrically mounted on the second shaft and configured to rotateabout the second shaft; a third mass eccentrically mounted on the firstshaft at a first angle relative to the first mass and configured torotate about the first shaft; and a fourth mass eccentrically mounted onthe second shaft at a second angle relative to the second mass andconfigured to rotate about the second shaft, wherein the third andfourth masses are respectively spatially separated from, and areconfigured to respectively act as partial counterbalance masses to, thefirst and second masses; and a drive system configured to selectivelygenerate elliptical, circular, and linear vibratory motion such that: ina first selectable configuration, the drive system imparts rotationalmotion to the first and second shafts to cause the first and secondmasses to rotate in a common direction to thereby generate elliptical orcircular vibratory motion of the eccentric vibrator; and in a secondselectable configuration, the drive system imparts rotational motion tothe first and second shafts to cause the first and second masses torotate in opposite directions to thereby generate linear vibratorymotion of the eccentric vibrator, the method comprising: selecting, viathe drive system, either the first selectable configuration or thesecond selectable configuration.
 24. The method of claim 23, furthercomprising controlling the drive system to control an angle of linearmotion by controlling relative angular positions of the first and secondmasses.
 25. The method of claim 24, further comprising controlling thedrive system to change an angle of linear motion from a first angle to asecond angle during operation of the eccentric vibrator.
 26. The methodof claim 23, further comprising controlling the drive system to changefrom linear motion to elliptical or circular motion during operation ofthe eccentric vibrator.
 27. The method of claim 23, further comprisingcontrolling the drive system to cause the first and second shafts torotate in opposite directions with a common frequency to generate linearvibrations.
 28. The method of claim 23, further comprising controllingthe drive system to cause the first and second shafts to rotate in thesame direction with a common frequency to generate circular vibrations.29. The method of claim 23, further comprising: monitoring a measurementdevice to measure an angular position and/or a velocity of the first andsecond masses; and controlling the drive system to control one or moreof rotational frequencies, directions, and relative angular positions ofthe first and second masses, based on measurements taken by themeasurement device.
 30. The method of claim 23, further comprisingcontrolling the drive system to control the vibratory motion to be alinear motion along a line that is oriented at an angle in a range fromapproximately 0 radians to approximately π radians relative to a fixeddirection.